It’s just a theory I have, and I could be wrong…. But I almost wonder if 5.2s have more boost pressure capability before blowing head gaskets than 5.9s due to the increased deck area from the smaller bore. Kinda like 4.8 and 5.3 is the “golden child” of sbe ls stuff. Smaller bore than ls1 6.0 etc so the cylinder head can clamp better. Maybe I’m wrong and it’s just a coincidence.